Question

In my winform application; I have login form and main form.

When I run program I want the login form on top and main form behind it.

One more thing is until I do not login properly with username and password, the main form should not be accessible and only the login form should accessible.

My Language is C#.Net.

Please provide idea on how to achieve this?

Answer 1

Use Form.ShowDialog (Shows the form as a modal dialog box) on the your Form.OnShown event (Occurs whenever the form is first displayed):

private void Form1_Load(object sender, EventArgs e)
{
    this.Shown += Form1_Shown;
}

private void Form1_Shown(object sender, EventArgs e)
{
    LoginForm loginForm  = new LoginForm ();

    if (loginForm.ShowDialog() == DialogResult.Ok)
    {
     ....
    }
}

your Program and LoginForm like this:

//Progrmm.cs
Application.Run(new Form1());

//LoginForm.cs
public partial class LoginForm : Form
{
    public LoginForm ()
    {
        InitializeComponent();
    }

    private void buttonLogin_Click(object sender, EventArgs e)
    {
        //check username password
        if(texboxUser == "user" && texboxPassword == "password")
        {
            DialogResult = DialogResult.OK;
            Close();
        }
        else
        {
            MessageBox.Show("Wrong user pass");
        }
    }
}